Stalking is amongst the most insidious and terrifying of crimes for its victims, eroding their sense of security and pitching them into a state of fear in which they never feel safe.

The imprisonment of the former BBC Leeds presenter Alex Belfield for five-and-a-half years for a series of stalking offences is a measure of how seriously the courts view such criminality.

One of his victims, radio and television presenter Jeremy Vine, articulated the effect online stalking has, speaking of how he feared for his family’s safety.

Belfield had, he said, “weaponised” the internet by motivating hundreds of thousands of followers to join his campaign of abuse.

Ex-BBC presenter Alex Belfield on his phone outside court during his trial in Nottingham.

His harrowing testimony, and criticism of the social media Belfield used to abuse him, including YouTube and Twitter, raises wider issues.

Both those platforms failed to take down frightening posts, which led Mr Vine to accuse them of lacking moral values.

Many will agree.

Social media giants have long evaded responsibility for offensive content by hiding behind the conceit that they are not publishers, merely platforms for material created by others.

This effectively allows them to sidestep regulations that apply to mainstream media, whether in print, broadcast or online.

Belfield’s cruelty and conviction have highlighted the need for this anomaly to be addressed, if necessary by new legislation.

It is unacceptable that anybody should be subjected to vile abuse that puts them in fear of their lives, whilst the media being used to inflict terror claim it has nothing to do with them.

Disturbing Alex Belfield case shows YouTube and Twitter must act against stalkers - The Yorkshire Post says